1. Field of the Invention
The present invention relates to a three-dimensional stereolithography apparatus that forms a three-dimensional object from a light-curing material, a three-dimensional stereolithography method, and a three-dimensional object formed by a three-dimensional stereolithography method.
2. Description of the Related Art
From the past, a modeling apparatus that forms a three-dimensional object is known as an apparatus that performs so-called rapid prototyping and is widespread for commercial use. Generally, a three-dimensional modeling apparatus models a three-dimensional object by forming layers one by one based on shape data for each predetermined thickness of a target object to be modeled, that is, based on shape data of each layer.
As a main system of a three-dimensional modeling apparatus, a stereolithography system partially selectively irradiates a light-curing resin with laser light, and thus cures and traces a desired part of the resin, thereby forming a three-dimensional object.
The stereolithography system includes a free liquid level method and a restricted liquid level method, for example. In the free liquid level method, the liquid level of a light-curing resin is exposed to air, and laser light is focused on an interface between air and the liquid level, thereby making a tracing. The free liquid level method has a problem in that layering accuracy (accuracy of a thickness for each layer or accuracy of a surface condition of a resin for each layer) of a resin varies depending on surface accuracy of a liquid level. In view of this, in a restricted surface level method, the liquid level of a light-curing resin is restricted by a flat glass surface, and laser light is focused on an interface between the liquid level and the glass surface through the glass, thereby making a tracing (see, for example, Japanese Examined Patent Publication No. H7-84033, paragraph 0018 (hereinafter, referred to as Patent Document 1)). In Patent Document 1, a film is used as a member that restricts a liquid level.